Field of the Invention
This invention relates to a display apparatus, especially to a driver having a polarity inversion control function applied to a display apparatus.
Description of the Related Art
In general, in the application of the LCD display panel, when a voltage on the electrode is provided to the liquid crystals through the orientation layer, the DC blocking effect failing to change the arrangement of the liquid crystals and the DC residue effect of the moveable ions around the liquid crystals driven by the voltage may be generated.
Therefore, lots of pixel matrix polarity inversion methods, such as frame inversion, column inversion or dot inversion, are used to drive the liquid crystals to solve the above-mentioned problems. Because these three polarity inversion methods have their own drawbacks respectively, a polarity inversion method of (2V+1) dual line dot inversion is developed based on the column inversion and the dot inversion.
When the display panel is verified, some “killer patterns” are usually used to verify the quality of the pixels of the display panel. For example, as shown in FIG. 1, the frame of 3V3H pixel matrix under dot inversion is light and dark staggered. For the display lines L1˜L6, the polarity output sequence of the display lines L1, L3 and L5 is (+,−,+,−,+,−); the polarity output sequence of the display lines L2, L4 and L6 is (−,+,−,+,−,+). The output channels CH60 and CH63 correspond to the red color (R); the output channels CH61 and CH64 correspond to the green color (G); the output channels CH62 and CH65 correspond to the blue color (B). At this time, the output data signals and polarities of the output channels CH60˜CH65 are shown in FIG. 2A˜FIG. 2C respectively.
It should be noted that under the ideal condition, the common voltage VCOM of the display panel will be fixed to a certain level, as shown by the dotted lines of FIG. 2A˜FIG. 2C. However, in practical applications, because the output voltage will pull the common voltage VCOM of the display panel through the thin-film transistor TFT, the common voltage (VCOM) jitters occur on the conventional display panel, as shown by the bold lines of FIG. 2A˜FIG. 2C. At this time, the frame displayed by the display panel will be abnormal due to the common voltage (VCOM) jitters of the display panel, such as color deviations of the frame.